Contour Enthusiasts Group Archives Forums General Troubleshooting surging like slip in tranny after 20 mins' driving

Contour GL 1995 133000 miles,
4 Cylinders 122 3 2.0L SFI DOHC
tune up a month ago, tranny fluid changed one week ago.

The car rans good at the beginning, even over 60 mph. After about 20 mins' driving, the engine warmed up, when speed over 40 mph, the car begain surge like slip in tranny. You also can hear the thump. When pushing the gas pedal, the Gas rushed out more than the normal.

When open the hood, I heard the periodic sound like leaking from the engine.

What's wrong with my car?

The PCV valve is bad? or ...

Welcome . If you haven't changed the PCV valve in 60K miles, try that. In addition, drive to Autozone or Advance, scan for Check Engine light codes and post the exact codes.

With a 1995 OBD I, you can get the codes yourself.
Click this thread

I just replaced a new PCV vavle.

But the Surging still happens afte 20 mins driving.

the slip, jerk and clunk in tranny come together when speed over 40 mph especially pushing the gas pedal.

Could anybody tell me the reasons or give me some suggestions, thanks very much.

No light on; No code

There is a chance your tranny is about to break down. A one hour diagnostic from a good tranny shop should confirm it.

If it were me, I would change the ATF 2 more times. We have a how to for that. ATFluid 3X drain and refill

Then, I would check/change the MLPS and see if it helps.

Edit.
Check engine/tranny mounts too.

Check Manual lever position sensor and cable.
MLPS change

Cable below tranny shift lever

And from Autozone

THanks a lot.